Interpretive Summary: We explored the relationship between DNA sequence variation in the apolipoprotein E (apoE) gene and stroke in 15,792 men and women, aged 45 to 64 years at baseline, from the Atherosclerosis Risk in Communities Study (ARIC). Between 1987 and 2001, 498 strokes occurred. After analyzing the subjects separately by race and sex and adjusting for other risk factors, there was no significant relation between the apoE gene and stroke, except in black women. For the most part, in this middle-aged sample, apoE was not a risk factor for stroke.

Technical Abstract:
BACKGROUND AND PURPOSE: A relationship between the apolipoprotein E (apoE) genotype and ischemic stroke has been inconsistently reported. We explored this relation in the Atherosclerosis Risk in Communities Study (ARIC). METHODS: The ARIC cohort involves 15,792 men and women, aged 45 to 64 years at baseline and sampled from 4 U.S. communities. Between 1987 and 2001, 498 incident ischemic strokes occurred.
RESULTS: After stratifying by race and sex and adjusting for other nonlipid risk factors, there was no significant relation between the apoE genotype and incident stroke, except in black women (hazard ratio for epsilon2 genotype relative to epsilon3/epsilon3=0.53; 95% CI, 0.28 to 0.99).
CONCLUSIONS: For the most part, in this middle-aged sample, apoE was not a risk factor for incident ischemic stroke.